Valve mechanism for steam engines



Sept. 28, 1937. H, MUELLER 2,094,159

V ALVE MECHANISM FOR STEAM ENGINES Filed Aug. 31, 1956 '4 Sheets-Sheet 1 fv c M I ATTOR EYS.

Sept. 28, 1937. H. G. MUELLER VALVE MECHANISM FOR STEAM- ENGINES Filed Aug. 51, 1936 1 4Sheets-Sheet 2 WWW IN V EN TOR.

BY 7%, M ATTOR EYS.

Sept. 28,1937. H. e. MUELLER I VALVE MECHANISM FOR STEAM ENGINES 4 4 Sheets-Sheet 3 Filed Aug. 51, 1936 HN IIIIIIIIIIIIIIJ A IIIHh ATTORNEYS.

Sept. 28, 1937. H. 5. MUELLER 2,094,159

VALVE MECHANISM FOR STEAM ENGINES Filed'Aug. 31, 1936 4 SheetsSheet 4 IN VEN TOR.

/MMMV ATTORNEYS.

Patented Sept. 28, 1937 PATENT OFFICE VALVE MECHANISM FOR STEAM ENGINES Herman G. Mueller, Erie, Pa., assignor to Skinner Engine Company, Erie, Pa., a corporation of Pennsylvania Application August 31, 1936, Serial No. 98,697

21 Claims.

This invention is designed to improve the valve mechanism as used in steam engines. The cutoff for steam engines using poppet valves is commonly accomplished by controlling the action of the reciprocating poppet valve. In the present invention this is accomplished by providing a telescopic control sleeve, into and out of which the poppet valve moves as it is actuated toward and from its seat. Thusthe cut-off is accomplished by the telescopic action and tightness is accomplished by the seating of the valve. The cut-off controlling sleeve may be manually or automatically varied to vary the cut-off. Preferably the invention involves the use of such cutoff sleeve with a double beat valve and as exemplified is so shown.

The invention also contemplates a double beat valve sleeve passing steam through both ends of the valve. By so constructing the valve it is possible to reduce the diameter of the valve while maintaining the same passage capacity. The smaller valve reduces the clearance passages and thus adds to the economy of the engine and also reduces the size and expense of making the parts. Further features and details of the invention will appear from the specification and claims.

A preferred embodiment of the invention is illustrated in the accompanying drawings, as follows:

Fig. 1 shows a central section through the engine on the line II in Fig. 2.

Fig. 2 an elevation of the engine partly in section. 7

Fig. 3 a detached View of modified valve cam mechanism.

Fig. 4 an enlarged view of one of the valves illustrated in Figs. 1 and 2m section on the line I-I inFig. 2.

Fig.5 a section on the line 5--5 in Figs. 1 and 4.

Fig. 6 shows a valve adapted to a horizontal cylinder, the valve being arranged vertically, and modified in construction.

, Fig. 7 shows a section on the line 'I'I in Fig. 6.

Fig. 8 shows the valve mechanism of Figs. 1 and 2 applied to a multi-cylinder engine, illustrating the manner of plural control from a single governor.

I marks an engine frame, 2 a cylinder, 3 inlet ports leading to the cylinder, 4 the centrally arranged exhaust ports for uniflow operation of the cylinder, 5 a piston operating in the cylinder, 6 a piston rod secured to the piston and extending through a gland I, the piston rod being secured to a crosshead 8 suitably guided on the engine frame. A connecting rod 9 extends from the crosshead to a crank Ill. The crank is carried by the crank shaft I I, the crank shaft being journaled in bearings I2 on the frame. 7

The valve mechanisms at both ends of the cylinder are substantially alike, each has a valve 5 chest I3 which is provided with a cover I4. The chamber has an inner steam passage I5 leading to the port 3.

Valve seats I6 and I! are provided, these being of comparatively common construction, and are 10 arranged in accordance with prior practice. The seat I1 is carried by a yielding ring I8 sealed by a sealing ring I9, and yieldingly held in place by spring 26. A look ring 2I holds the yielding seat ring I8 in place, having sufficient clearance to permit the yielding of the ring.

A valve 22 is made in two parts, 23 and 24. The part 23 has a seating edge operating on the seat I6, and part 24 has a seating surface 26 operating on the seat II. valve have the closed skirts 21 which extend from hub portions 22a through which the valve stem 29 extends. The valve stem has a shoulder engaging the part 23 on the valve, and a nut 3| engages the part-24 to clamp the parts of the 25 valve together. A spring 28 tends to hold the valve in closed position.

The valve stem 29 has a slotted head 32, and an operating lever 33 extends through this slot in position to lift the valve. The slotted stem head 32 carries an adjusting screw 32a with lock nut 32b. The lever 33 is pivoted on a pin 34 carried by bracket 35 extending from the cover I4.' The lever 33 is connected to an arm 36 forming a bell crank, and the arm 36 is engaged by a push pin 31 with adjustable screw 31b and slidingly mounted in a cam box 38. The pin 31 terminates in a roller 31a or a mushroom 31c with the construction shown in Fig. 3. A cam 39 has actuating cam surfaces 40, one for each valve. The cam 39 is fixed on a shaft M which extends through the wall of the cam box 38, and a rock arm 42 is secured to the outer end of the shaft. The rock arm is connected by rod 43 with an eccentric 44. The eccentric 44 is mounted on the crank shaft II, so that its angular relation to the crank is adjustable. Preferably the length of the rock arm 42 is also adjustable. This is accomplished by providing the rock arm 42 with a slot 45. A pin 46 connecting the rod 43 has a shoulder 41, the pin extending through the slot 45. A nut 48 on the end of the pin clamps the shoulder 41 in place on the arm and thus locks the pin 46 in the adjustment. Normally the lift and lead of the valve through this mechanism is The two parts of the constant, the adjustment being provided to give to the valve as high a lift as is practical for the particular purpose for which the engine is being used, and a suitable lead. Where the load is practically constant this may be a comparatively low lift. Where there is greater variation a higher lift with longer duration is utilized to give a wider range of cut-o1f A cut-01f sleeve W is slidingly mounted in the valve case in a cylindrical opening 50. The valve end 23 has an interiorly arranged cylindrical surface 5! which is adapted to make atelescopic fit with the exterior on the sleeve 38. The outer surface of the valve portion 25 has a cylindrical surface 52 adapted to fit telescopically the inner surface of the sleeve G9. This sleeve forms a passage 53 around the valve leading from the seat 25 which forms a means of communication from the opening at the seat it with openings 54 through the sleeve leading to the chamber l5 and hence to the port 3.

Steam for passing the seat ll comes in through the ring l8 and passes immediately to the passage I5. The openings 56 leave cylindrical portions 55 at the ends of the sleeve and these cylindrical ends have the cut-off edges 5%: and 5'! operating with relation to the seating edges 25 and 26 respectively of the valves. In operation the sleeve is moved to vary the cut-off.

As shown in Fig. 4 the sleeve effects no cut-off so that there is the maximum opening of the valve. As the sleeve is moved toward the right in that figure, the cut-off edges 56 and 5'! are brought into position so that the cylindrical portions 56 and 52 pass into telescopic relation at an earlier point in the closing movement of the valve. By varying the position of the sleeve the point of cut-off may be controlled. After the cut-off is accomplished, the valve continues in its closing movement and finally completes the more certain closure on the seats l6 and ii. The cylindrical fit between the surfaces of the sleeve and the valve surfaces may be made as close as is practical-with ordinary working conditions. With the oscillating cam as indicated in Fig. 4 there is a slight variation in the lead as the sleeve is moved to change the cut-off but this variation is comparatively slight, as the lift takes place during the slow movement of the piston whereas the cut-off takes place during the more rapid movement of the piston. Consequently the slope of the lift diagram is much steeper on the lifting side than on the seating side. Where the rotating cam is used as in Figs. 3 and 8, the lifting side and seating side may be altered to suit any condition desired.

In order to adjust the sleeve a crank 58 is arranged to operate in an opening 58a in the wall of the sleeve. The sleeve rotates to accommodate the rocking movement of the crank, and the crank operates to move the sleeve axially to its desired adjustment. The crank is carried by crank shaft 59 journaled in a bearing 60 in the wall of the steam chest.

The shaft 59 of the upper valve is connected with a rock arm 6%, and this rock arm is connected through a pin 62 with a rod 63 which is connected with a rock arm 65 on the crank shaft of the lower valve by means of a pin (it. The rock arm 65 is connected through a bearing 66 with a rod Bl which rod extends to a bell crank lever 68. The bell crank lever 58 is mounted on a pin 69, and this pin is mounted in the engine frame. The opposite end ll! of the bell crank extends into a groove ii in a sleeve 12. The

sleeve :12 is slidingly mounted on the crank shaft. It is provided with a second groove 13 which is adapted to receive the ends of the lever arms 74. The lever arms are pivotally mounted on pin 15 carried by head F16. The head 18 is fixed on the crank shaft. Governor weights ll are rigidly secured to the lever arms l4 and their centrifugal action is balanced by spring l8 connecting these weights.

The operation of the mechanism may be followed from the above description. The double beat valve operating in the ordinary manner of double beat valves, from the cam mechanism driven from the crank shaft. The sleeve which telescopically operates with relation to the valve surfaces has the cut-off edges operating on the valves so that the cut-off is accomplished in accordance with adjustment of the sleeve. The governor through the linkage just described operates on the crank mechanism which moves the sleeve in accordance with the requirements of control so as to bring the cut-off edges together at an earlier or later part of the engine stroke, according to the requirements of the engine.

In the structure shown in Figs. 1 and 2 the cam 39 is of the rocker type and is made in this form preferably in order that the lift of the valve may be adjusted, but in very many cases this adjustment is not required and therefore a rotating cam may be used. This is shown in Fig. 3 where a rotary cam 39 is adapted to operate on the opposed push rods Bl. This cam is mounted on a shaft 89 driven by a chain 88 from the crank shaft.

In Fig. 6 the valve is adapted to a vertical arrangement on a horizontal cylinder. In this, the cylinder 8?; has an inlet port 83 leading from a valve chest 85. The valve chest is provided with valve seats 88 and fil and with an annular chamber receiving steam passing by these seats and leading the steam to the port 83. The valve 89 is of the ordinary double-beat type having the seating surfaces 99 operating on the seats 86 and 81. The valve has the usual spider connection between the valve seating portions and the central hub 92. A stem 92a extends through this hub and is secured thereto, it being understood that this central portion of the valve passing webs 9! is hollow so as to afford passage of the steam. Steam is delivered through the valve past the bottom seat, and from the steam chest a past the upper seat. The cut-off sleeve 93 corresponds to the cut-off sleeve in Figs. 1 and 2 and has the cut-off edges 95 and 96 operating in conjunction with the upper and lower parts of the valve, the upper part having an interior cylindrical surface, and the lower part an outer cylindrical surface similar to that of Fig. l and Fig. 4 for operating telescopically with relation to the cut-off sleeve. The sleeve also has openings 93a leading to a passage 8t, communicating with the port, 83.

This sleeve, by reason of the fact that the steam to pass the lower seat must go through the valve, is quite large compared to its length. The single crank for operating the sleeve shown in Figs. 1, 2 and 4 would tend to cook the valve as its diameter is large compared with its length. To obviate this difficulty, the structure in Figs. 6 and '7 provides a crank at both sides of the sleeve. To accomplish this, a block 91 is inserted in the steam chest, this block providing the lower seat 81 and a bearing for the lower end of the sleeve. The block has an opening 9M extending through it in which a crank shaft 98 is journaled. A crank 99 extends from the shaft at each end, the cranks having crank pins I extending into an annular groove It. This groove IIIIis formed in the interior surfaces of the projections I82 at the bottom of the sleeve. The crankshaft is connected outwardly by means of a flexible coupling 98a and extension 98b through the steam chest wall and is provided with a rock arm I03 to which a controlling mechanism is attached in the same manner as to the rock arm M. In order that the valve may be assembled from the end of the chest, the projections I 02 permit the insertion-of the sleeve which is thenturned to pass by the crank pins. After the sleeve is in its lower position it is rotated to bring the pins into the'groove Hit.

The sleeve is locked against rotation in this position by a screw I which extends in a vertical slot I04 in the sleeve. The block 97 is cut out at IDE- to permit of operating the screw m5.

I have shown schematically a pressure regulator 85b which may be connected as indicated by the "connecting lines with the operating lever I03 so'as to afford a pressure control. The slight movement of the sleeve necessary for ordinary control is particularly adapted for automatic control in this-way, since the sleeve is balanced for axial movement by equal opposed surfaces and I steam pressures for all positions of both sleeve and valve in all constructions shown and, therefore, offers very little resistance'to axial movement for either hand orautomatic controls.

In Fig. 8 the manner of controlling the valve mechanism for a multiple cylinder engine is illustrated. The individual cylinders with the valve mechanisms are similar to those of Figs. 1 and 2. A rotating cam is utilized as illustrated in Fig. 3. The cam shaft 80 is hollow,.and a controlling pin I97 extends through this shaft. A governor having Weights I08 pivotally mounted on a head I59 secured on one end of the shaft 80. The weights have the lever arms I III which operate in a spool III on the rod I01. A spring H2 operates against theopposite end'of-the rod I01 and balances the centrifugal force of the governor. A bell crank lever H3 is pivoted on a pin- I I3a, the pin being mounted on a bracket/H4 extending from the end of the cam box. The lever II3 engages a spool I I5 on the end of the rod I01. The lever I I3 is connected by rod I I6 with a rock arm I II. The rock arm is fixed on a rod H8 extending along the frame II9 of the engine. Bearings I20 are mounted on the frame to carry the rod IIB. Rock arms IZI, one for each cylinder, are fixed on the shaft I I 8, and rods I22 corresponding to rod 61 in Fig. 1 extend from the arms IE! to the rock arms 65 of the valve mechanism, and from this by a linkage and mechanism described with relation to Figs. 1 and 2 with the cut-off sleeves. Thus it will be seen by very simple governor mechanism a multiple cylinder engine may be formed with as many cylinders as desired and all controlled from the same governor.

The structure is particularly adapted as a reversing mechanism in that the telescopic cut-off permits the making of the two-way cams with a desirable slope for seating without sacrifice of economy.

While I have exemplified the invention as a valve mechanism as used in a steam engine, it will be understood that it is effective with any expansive fluid.

What I claim as new is:

1. In a valve mechanism, the combination of a poppet valve; seats for said valve; closure surfaces operating telescopically on the valve; and

means varying the relation of said surfaces for controlling the cut-off of the valve.

2. In a valve mechanism, the combination of a poppet valve; seats for said valve; closure surfaces operating telescopically on the Valve; and speed responsive means varying the relation of said surfaces controlling the cut-off of thevalve.

3. In a valve mechanism, the combination of a poppet valve having poppet seating surfaces and cylindrical closing surfaces; seats for said poppet surfaces; and a sleeve having telescopic relation with the cylindrical-surfaces controlling the cutoff of the valve.

4; In a valve mechanism,; the combination of a poppet valve having poppet seating surfaces and cylindrical closing surfaces; seats for said poppet surfaces; a sleeve having; telescopic relation with the: cylindrical surfaces controlling the cut-off of the valve; and means varying the relation of the valve and sleeve to vary the cut-off.

5. In a valve mechanism, the combination of a poppet valve having poppet seating surfaces and inwardly faced closing surfaces; seats for said poppet surfaces; and a sleeve having telescopic rel tion with the closingv surfaces controlling the cu -0lf of the valve.

6. In a valve mechanism, the combination of a poppet valve having poppet seating surfaces and outwardly faced closing surfaces; seats for said poppet surfaces; and a sleeve having telescopic relation with the closing surfaces controlling the cut-off of the valve.

'7. In a valve mechanism, the combination of a poppet valve having poppet seating surfaces and cylindrical closing surfaces; seats for said poppet surfaces; a sleeve having telescopic relation with the cylindrical surfaces controlling the cut-off of the valve; and a crank operating onthe sleeve to vary the cut-off.

8. In a valve mechanism, the combination of a poppet valve having poppet seating surfaces and cylindrical closing surfaces; seats for said poppet surfaces; a sleeve having telescopic relation with the cylindrical surfaces controlling the cut-01f of the valve; a crank operating on the sleeve to vary thecut-ofi; and a speed responsive means actuating the crank.

9. In a valve mechanism, the combination of a poppet valve; seats for said valve; closure surfaces operating telescopically on the valve; means varying the relation of said surfaces for controlling the cut-ofi. of the valve; and means varying the lift of the valve.

10. In a valve mechanism, the combination of a poppet valve having poppet seating surfaces and cylindrical closing surfaces; seats for said poppet surfaces; a sleeve having telescopic relation with the cylindrical surfaces controlling the cut-off of the valve; and means varying the lift of. the valve.

11. In a valve mechanism, the combination of a poppet valve having poppet seating surfaces and cylindrical closing surfaces; seats for said poppet surfaces; a sleeve having telescopic relation with the cylindrical surfaces controlling the cut-off of the valve; means varying the relation of the valve and sleeve to vary the cut-oif; and means varying the lift of the valve.

12. In a valve mechanism, the combination of a double-beat poppet valve; seats for said valve; closure surfaces operating telescopically on said valve with relation to each seat; and means varying the relation of said surfaces to control the cut-off of the valve.

' 13. In a valve mechanism, the combination of a double-beat valve having poppet valve seating surfaces and cylindrical closing surfaces with relation to each seating surface; seats for said seating surfaces; and a sleeve having telescopic relation to the closing surfaces controlling the cut-off of the valve at each seat.

14. In a valve mechanism, the combination of a double-beat valve having poppet valve seating surfaces and cylindrical closing surfaces with relation to each seating surface; seats for said seating surfaces; a sleeve having telescopic relation to the closing surfaces controlling the cut-off of. the valve at each seat; and means varying the relation of the valve and sleeve to vary the cutoff.

15. In a valve mechanism, the combination of a double-beat valve having poppet valve seating surfaces and cylindrical closing surfaces with relation to each seating surface, one of the cylindrical surfaces being outwardly faced and the other of the cylindrical surfaces being inwardly faced; seats for said seating surfaces; and a sleeve having telescopic relation to the closing surfaces controlling the cut-off of the valve at each seat.

16. In a valve mechanism, the combination of. a double-beat valve having poppet valve seating surfaces and cylindrical closing surfaces with relation to each seating surface; seats for said seating surfaces; and a sleeve having telescopic relation to the closing surfaces, said sleeve having openings therethrough and closing edges with relation to said seating surface, one closing edge being at the end of the sleeve and the other closing edge being at the opening, said edges con trolling the cut-off of the-valve.

17. In a valve mechanism, the combination of a double-beat poppet valve; a chest for said valve having seats for the seating surfaces of said valve, said chest having communication outside of the valve with each end of. the valve; closure surfaces operating telescopically on said valve with relation to each seat; and means varying the relation of said surfaces to the valve to control the cutoff of the valve.

18. In a valve mechanism, the combination of a poppet valve having poppet seating surfaces and cylindrical closing surfaces; seats for said poppet surfaces; a sleeve having telescopic relation With the cylindrical surfaces controlling the cut-off of the valve; cranks engaging opposite sides of said sleeve for varying the position of the sleeve relatively to the valve; and means actuating said cranks.

19. In a valve mechanism, the combination of a poppet valve having poppet seating surfaces and cylindrical closing surfaces; seats for said poppet surfaces; a sleeve having telescopic relation with the cylindrical surfaces controlling the cut-off of the valve, said sleeve having downwardly extending portions having transverse slots on the inner faces of said portions; cranks extending into the slots for actuating the sleeve; and means actuating the cranks.

20. In a valve mechanism, the combination of a plurality of valve mechanism units, each comprising a poppet valve; seat for said valve; closure surfaces operating telescopically on the valve; and means varying the relation of said surfaces for controlling the cut-off of the valve, said means comprising an actuating device common to all the units.

21. In a valve mechanism, the combination of. a series of valve mechanism units, each comprising a poppet valve having poppet seating surfaces and cylindrical closing surfaces; seats for said poppet surfaces; a sleeve having telescopic relation with the cylindrical surfaces controlling the cut-off of the valve; and a cam mechanism comprising a cam shaft actuating the valves of the series, said shaft being hollow, a governor mounted on the cam shaft, a governor stem extending through the shaft, and means connecting the governor stem to the valves for controlling the cut-off.

HERMAN G. MUELLER. 

